The present invention relates to a battery unit holding device for a vehicle.
A battery unit holding device for a vehicle is disclosed in Japanese Unexamined Patent Application Publication No. 2013-67334 . The battery unit holding unit has a deformable bracket between the vehicle body and the battery unit. The deformable bracket supports the load acting downwardly on the battery unit between the vehicle body and the battery unit. If an impact is applied to the vehicle in its width direction, the vehicle body may be deformed or crushed in the width direction by the impact, and an inertial force corresponding to the impact may act on the battery unit. When an impact whose magnitude is greater than a specified magnitude is applied to the vehicle in the vehicle width direction, the bracket is deformed thereby to permit the battery unit to move or to be displaced in the width direction of the battery unit relative to the vehicle body. Therefore, in the event of application of an impact to the vehicle, the battery unit holding device suppresses damages incurred by the battery unit, while holding the battery unit in place in the lower part of the vehicle body.
Japanese Unexamined Patent Application Publication No. 2006-182099 discloses a battery unit holding device for a vehicle of a different type. The battery unit holding device has a battery frame provided in the vehicle and a bolt. The battery frame has an elongated hole extending in the vehicle width direction. The bolt is fastened to the battery unit through the elongated hole with the bolt shank inserted through the elongated hole and the bolt head pressed in contact with the periphery of the elongated hole from above. The battery frame and the bolt cooperate to support the load on the battery unit acting downwardly between the vehicle body and the battery unit. The bolt is displaceable in the width direction within the elongated hole when an impact whose magnitude is greater than a specified magnitude is applied to the vehicle in its width direction, thereby permitting the battery unit to move in the width direction of the battery unit relative to the vehicle. Thus, the battery unit holding device according to this Publication also suppresses damages incurred by the battery unit, while holding the battery unit in place in the lower part of the vehicle body.
However, the battery unit holding devices disclosed in the above-cited Publications tend to become heavy in weight and to involve a high cost.
To be more specific, in the case of the battery unit holding device disclosed in Japanese Unexamined Patent Application Publication No. 2013-67334, making the deformable bracket strong enough to adequately support the load on the battery unit may involve an increase in the weight and the material cost of the battery unit holding device. Furthermore, designing and manufacturing of the bracket so as to be deformable without fail upon receiving an impact may also involve an increase in the manufacturing cost.
In the case of the battery unit holding device disclosed in Japanese Unexamined Patent Application Publication No. 2006-182099, on the other hand, making part of the battery frame around the elongated hole and the bolt strong enough to adequately support the load on the battery unit may also involve an increase in the weight and the material cost of the battery unit holding device. Designing a bolt having the fastening strength falling within the desired range requires a precise control of the fastening torque of the bolt, which may lead to an increase in the cost of tightening torque management.
The present invention which has been made in view of the above circumstances, is directed to providing a battery unit holding device for a vehicle that is practical in use, light in weight, and low in manufacturing cost.